The present invention relates to wireless communication and more particularly, an interference removal method in a multi-node system and a terminal using the method.
Recently the amount of data transmission in wireless communication networks is rapidly growing. This sharp increase in the amount of data transmission is largely attributed to machine-to-machine (M2M) communication and advent and wide use of various kinds of devices such as smart phones, tablet PCs, and so on. New technologies are emerging to meet the requirement for supporting the large amount of data transmission: carrier aggregation technology, cognitive radio technology, and so on for making an effective use of more frequency bands; and multi-antenna technology, multi-base station collaboration technology, and so on for increasing data capacity with limited frequency resources.
Current wireless communication networks are evolving into such a direction that density of nodes is getting higher. Here, a node refers to an antenna or a group of antennas placed apart from each other by more than a predetermined interval in a distributed antenna system (DAS) but the term can be used in a much broader sense without being limited to the definition above. In other words, a node may correspond to a pico-cell base station (PeNB), home base station (HeNB), remote radio head (RRH), remote ratio unit (RRU), relay, distributed antenna, and so on.
A wireless communication system having high density of nodes can show much better system performance by utilizing collaboration between the nodes. In other words, if each node operates as an independent base station (BS) (advanced BS (ABS), node-B (NB), eNode-B (eNB), access point (AP), and so on) and transmission to and from each node is managed by one control station and each node operates like an antenna (or a group of antennas) in one cell, much better system performance can be achieved compared with a case where the individual nodes do not collaborate with each other. In this case, a multi-node system can be called a distributed antenna system (DAS).
Similarly, a multi-node system can operate as a multi-cell system carrying out scheduling and handover with distinctive identifiers for the respective nodes. If a multi-cell system is configured in such a way that coverage of each node overlaps with each other, the system is called a multi-tier network.
An interference removal method which can be used in a multi-node system and a terminal using the method are necessary.